Split-Stream Zircon Petrochronology Analysis

Background
The U.S. Geological Survey (USGS) conducts research on regional geology and mineral resources, which includes making geologic maps and reconstructing tectonic and metallogenic history. The goal of this contract is to acquire U-Th-Pb and Lu-Hf isotopic data from zircon petrochronology analysis of rock samples to support geologic research and elucidate the geologic evolution of critical mineral ore systems in the United States.

Work Details
The contractor will perform split-stream laser ablation (LASS) zircon petrochronology analysis on approximately five (5) igneous or metamorphic rock samples. The work includes:
- Preparation of rock samples to obtain zircon mineral separates, which involves crushing, sieving, concentrating zircon using heavy liquids, and using a Frantz magnetic separator.
- Imaging and characterization of zircons using Backscatter Electron (BSE) and Cathodoluminescence (CL).
- Conducting split-stream (LASS) laser ablation analysis for U-Pb age determination and Lu-Hf isotopic analysis.
- Generation of analytical datasets and associated documentation, including both raw analytical data and interpreted results in spreadsheet format.

Period of Performance
The specific period of performance is not detailed but will be defined in the solicitation process.

Place of Performance
Analyses will be completed at the vendor’s facility.

Bidder Requirements
Interested vendors must demonstrate:
1. Laboratory capabilities for zircon petrochronology with experience in split-stream laser ablation (LASS) methods for both U-Pb and Lu-Hf analyses.
2. Description of instrumentation and analytical methods used, including laser ablation systems, mass spectrometry capabilities, and imaging techniques.
3. Experience performing similar geochronology or geochemical analysis services.
4. Examples of recent relevant work performed.
5. Quality assurance and quality control procedures, including standards use, analytical precision, and error reporting.
6. Ability to perform a minimum of 50 analyses per sample.
7. Description of data deliverables in specified formats.
8. Company information including business name, UEI number, and business size classification.

Incumbent Analysis (see Incumbents section for more detail)
This opportunity appears to have a confirmed incumbent based on prior contract 140G0326P0153 awarded to the University of Arizona for split-stream U-Th-Pb and Lu-Hf zircon analyses. The prior work involved performing split-stream laser ablation petrochronology on igneous or metamorphic samples (non-NSF-supported and ALC staff analyses), which aligns closely with the current requirement to prepare zircon separates, image zircons (BSE/CL), and generate U-Pb age and Lu-Hf isotopic datasets for similar sample types. The small scale of the prior effort (3 samples) relative to the current estimate (about 5 samples) suggests continuity in method and deliverables rather than a fundamentally different scope.